Anatomy: Thoracic outlet is the space between the first rib, clavicle/sternum, and spinal column: The subclavian artery, subclavian vein, and brachial plexus all pass through this area.

Symptoms:

• Neurogenic symptoms most common- pain, decreased/abnormal sensation, numbness, weakness; provoked by activities that involve elevation of arm and subsequent compression of brachial plexus
• Venous compression symptoms second most common - swelling, edema, pain, cyanosis
• Arterial compression symptoms least common - pain, pallor, paresthesia, poikilothermia, pulselessness

Pathogenesis:

• Developmental abnormalities (anomalous ribs, muscular anomalies)
• Injuries (inflammatory changes secondary to trauma - most commonly hyperextension/flexion of neck and rib fx)
• Repetitive overhead motions (throwing baseball, swimming)

Why relevant to ED Physicians?

Vascular compression from thoracic outlet syndrome leads to poststenotic dilation and possible secondary thrombus formation

Work up: CXR to evaluate for bony abnormalities and duplex ultrasound if arterial/venous compression suspected

Treatment:

• Neurogenic TOS initially managed with physical therapy as outpatient
• Venous TOS with evidence of thromboembolism needs systemic anticoagulation or catheter-directed thrombolysis
• Arterial TOS needs catheter-directed thrombolysis or surgery
• Thoracic outlet decompression surgery (surgical excision of cervical rib) indicated for patients with vascular TOS or severe/disabling neurogenic TOS

SOURCES

Fritz, David A.. "Chapter 40. Vascular Emergencies." CURRENT Diagnosis & Treatment. Emergency Medicine, 7e Stone C, Humphries RL. Stone C, Humphries R.L. Eds. C. Keith Stone, and Roger L. Humphries. New York, NY: McGraw-Hill, 2011,http://accessmedicine.mhmedical.com/content.aspx?bookid=385§ionid=40357256.

Engstrom, John W., and Richard A. Deyo.. "Back and Neck Pain." Harrison's Principles of Internal Medicine, 19e Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J. Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J Eds. Dennis Kasper, et al. New York, NY: McGraw-Hill, 2014, http://accessmedicine.mhmedical.com/content.aspx?bookid=1130&sectionid=79724373.